Re: [patch,libgfortran] PR28335 flush() / write() statement on closed units

[Michael Paton <mpaton at swbell dot net>]

I've just run across the effects of this in the 20060729 snapshot, where
previously working code got runtime errors. It seems that Jerry's patch
makes it an error to attempt to CLOSE a unit which has not been OPENED, or
"associated". My reading of the f77 standard and a late draft of the 2003
standard show this to be explicitly permitted. I couldn't easily access the
F90 or F95 standards.

When I get access again to my other system, I can file a bugzilla report, if
this is the appropriate thing to do.

As a user whose (possibly misguided) program stopped working, I'll also 
confess to some brief irritation at the error text, "Can't find specified 
UNIT in CLOSE". In essence, the runtime knows I want to do a CLOSE on a 
specific UNIT, and it
has a problem with that, but it won't tell me which UNIT. I'm afraid that 
looking at error.c didn't give me a clearer idea of how a more useful error 
message could have been given within the existing program structure.

Michael Paton


Jerry DeLisle wrote:
> I plan to commit to trunk the attached trivial patch in 24 hours.

> Regression tested OK after getting rid of a loose CLOSE(10) statement in 
> gfortran.dg/temporary_1.f90. Fixed test case attached has nothing to do 
with > I/O

> Regards,

> Jerry

> 2006-07-24 Jerry DeLisle <jvdelisle@gcc.gnu.org>

> 	PR libgfortran/258335
> 	* close.c (st_close): Add error when UNIT does not exist.
> 	* file_pos.c (st_flush): Add error when UNIT does not exist.



Index: io/close.c
===================================================================
*** io/close.c	(revision 115692)
--- io/close.c	(working copy)
*************** st_close (st_parameter_close *clp)
*** 102,107 ****
          unlink (path);
  #endif
      }
!
    library_end ();
  }
--- 102,109 ----
          unlink (path);
  #endif
      }
!   else
!     generate_error (&clp->common, ERROR_BAD_OPTION,
! 			    "Can't find specified UNIT in CLOSE");
    library_end ();
  }

! { dg-do run }
! PR 27662. Don't zero the first stride to indicate a temporary. It
! may be used later.